I Recently adjusted the exterior furnace gas vent pipe as per the picture below. The old placement ended where the first elbow (up/left looking at the pic) is currently. However given that my 2 year old son likes to play close to the garage door, the vent smoke was contently blowing in our face.
I purchased a couple of elbows and a few feet of pipe and extended it around and up.
Is this safe to do?
Is there a maximum length that the pipe needs to be?
My concern it extends too high and there may be CO coming back to the house. I have had it this way for a week, and have a CO detector in the furnace room with a 0 read.
Any advice would be appreciated because the last thing I want to do is put my family at harms way.
Best Answer
There's a possibility, but it's not very high.
The current vent is near the soffits, but the risk there is fairly minimal. It looks to be 1-2 feet from the pipe so there's some diffusing that will happen. It's also possible the warm exhaust will rise far enough to clear the soffit before it can reach it.
Even if the exhaust reaches the attic, your attic is designed to let the air flow freely inside, which would further diffuse it. It's unlikely any part of your attic is open to the interior. Even if you have, say, an attic door, we're talking minute traces that could actually get through it. In the winter (when you would be running the furnace) the heat from your house would be trying to get into the attic as well.
Regardless, it's always a good idea to have a carbon monoxide detector in your house. If something goes wrong with the furnace attachment to the exhaust, that could pose a far worse hazard.